1. Field of the invention
This invention relates to a switch of the type that the movable contact of the switch body slides as the operating member is turned.
2. Related Art
For instance, a motor vehicle has a power window mechanism with a switch designed as shown in FIG. 4. The switch has an operating member 3 which is provided on a vehicle body 1 in such a manner that it is turnable around the central axis 2. The operating member 3 has an arm 4 which is protrudes downward. The arm 4 has an engaging groove 4a in the end portion, which is engaged with a pin 5a embedded in a switch body 5. The pin 5a is coupled to a contact holder (not shown) holding a movable contact (not shown). Hence, as the operating member 3 is turned in the direction of the arrow "a", both the pin 5a and the movable contact slide along an elongated hole 5b as indicated by the two-dot chain line, so that the output signal of the switch body 5 is switched over to another one.
In order to smoothly operate the switch, the operating angle .theta. through which the operating member 3 is turned to switch the output signal is preferably of the order of fourteen (14) degrees. On the other hand, depending on the specification of the motor vehicle, the switch is large in height, and accordingly the arm is large in length L.
In this case, the slide stroke S of the pin 5a of the switch body 5 may be calculated by the following equation: EQU S=L sin .theta.
Hence, if the operating angle .theta. of the operating member 3 is set to 14.degree., the ideal value, then the slide stroke S of the pin 5a is large, so that the movable contact may move past the predetermined point. Thus, in the case where the length L of the arm 4 is large, the operating angle .theta. of the operating member 3 must be decreased in proportion. In this case, it is impossible to employ the ideal operating angle to switch the output signal which allows the switch to operate most smoothly.
In view of the foregoing, an object of this invention is to provide a switch which is so designed that, even if the switch is large in height, the switch output signal can be achieved with the ideal operating angle which allows the switch to operate most smoothly.